616
FXUS65 KVEF 060839
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
139 AM PDT SUN SEP 6 2026
KEY MESSAGES
* A BAND OF SHOWERS WITH A CHANCE OF EMBEDDED THUNDERSTORMS WILL
FORM ALONG INTERSTATE 15 THIS MORNING AND AFTERNOON.
* DRIER CONDITIONS EXPECTED FOR LABOR DAY, WITH DECREASING
CONFIDENCE IN MONSOONAL THUNDERSTORMS THROUGH THE WEEK.
DISCUSSION
TODAY THROUGH SATURDAY.
A SURGE OF MOISTURE REMINISCENT OF A WINTER-TYPE SYSTEM IS PUSHING
NORTHWARD IN A LINE FROM SAN DIEGO THROUGH NEEDLES INTO NORTHERN
ARIZONA EARLY THIS MORNING THANKS TO MOISTURE FROM HURRICANE MARIE.
THE UPPER-LEVEL TROUGH RESPONSIBLE FOR USHERING THIS MOISTURE INTO
THE DESERT SOUTHWEST WILL ALSO GUIDE A SHORTWAVE AND AN ASSOCIATED
115 KT 150MB JET STREAK INTO THE REGION. THE COMBINATION OF THESE
FEATURES WILL RESULT IN A LINE OF SHOWERS (AND POTENTIALLY EMBEDDED
THUNDERSTORMS) FORMING SOUTHWEST-TO-NORTHEAST ACROSS OUR FORECAST
AREA, GENERALLY ALONG INTERSTATE 15. THIS BAND OF PRECIPITATION IS
CURRENTLY FORECAST TO BE QUITE NARROW, WITH NORTHWEST AND SOUTHEAST
CORNERS OF OUR FORECAST AREA REMAINING DRY - AND EVEN, FOR SOME,
EXPERIENCING MOSTLY SUNNY SKIES. THAT SAID, MINOR SHIFTS IN THE
POSITION OF THE MOISTURE FLUX COULD RESULT IN PREVIOUSLY FORECASTED
DRY LOCATIONS OBSERVING MEASURABLE RAINFALL. MOSTLY CLOUDY SKIES
THROUGHOUT THE MOJAVE DESERT AND SOUTHEASTERN GREAT BASIN THIS
MORNING WILL PREVENT MUCH IN THE WAY OF SBCAPE THROUGH THE
AFTERNOON. AS A RESULT, LIFT WILL BE LARGELY DEPENDENT ON
OROGRAPHICS - MEANING, THE GREATEST CHANCE OF LIGHTNING AND/OR HEAVY
RAINFALL WILL BE IN THE HIGHER TERRAIN. LOOKING AT CHANCES OF
RECEIVING 1 INCH OF RAINFALL OVER THE NEXT 24 HOURS, THE HREF
CONTINUES TO PAINT 60-70 PERCENT OVER THE HIGHER ELEVATIONS OF MT.
CHARLESTON AND 30-40 PERCENT OVER THE MOUNTAINS OF EASTERN LINCOLN
COUNTY. GIVEN THE TRAJECTORY OF THIS MOISTURE, THE LAS VEGAS VALLEY
IS LIKELY TO EXPERIENCE A SUBSTANTIAL AMOUNT OF RAIN-SHADOWING,
RESULTING IN MUCH LOWER FORECAST PRECIPITATION AMOUNTS (GENERALLY
BETWEEN 0.15 AND 0.30 INCHES). THAT SAID, SHOULD THE TRAJECTORY GAIN
A GREATER SOUTH-TO-NORTH COMPONENT, MOISTURE WOULD FUNNEL DIRECTLY
INTO THE LAS VEGAS VALLEY, RESULTING IN GREATER RAINFALL AMOUNTS
(THE 90TH PERCENTILE APPROACHES 0.50 INCHES). THE PRIMARY CONCERN
TODAY WILL BE THE TRAINING OF STRONGER CELLS EMBEDDED IN THE
PRECIPITATION BAND RESULTING IN NUISANCE PONDING OR EVEN FLASH
FLOODING, PARTICULARLY IN LOCATIONS LIKE PAHRUMP, WHICH WILL
EXPERIENCE SUBSTANTIAL RUNOFF FROM THE SOUTHWESTERN SIDE OF THE
SPRING MOUNTAINS. IN GENERAL, THE FLASH FLOOD THREAT IS EXPECTED TO
BE VERY ISOLATED, IF ANY AT ALL, DUE TO THE STRATIFORM NATURE OF
THIS PRECIPITATION. PRECIPITATION WILL GRADUALLY SUBSIDE LATE-
AFTERNOON INTO THE EVENING.
THERE IS DECREASING CONFIDENCE IN THE RETURN OF MONSOONAL
PRECIPITATION THIS WEEK, AS THE FOUR CORNERS HIGH SHIFTS SLIGHTLY
WESTWARD. PWATS IN EXCESS OF 1 INCH WILL REMAIN TRAPPED BENEATH THE
RIDGE, WITH LITTLE INSTABILITY ASIDE FROM DAYTIME HEATING. AS A
RESULT, CANNOT COMPLETELY RULE OUT ISOLATED CONVECTION, PARTICULARLY
IN THE MOUNTAINS. THROUGH THE WORK WEEK, TEMPERATURES WILL INCREASE
THANKS TO RISING HEIGHTS, WITH THE CENTER OF THE HIGH OVERHEAD BY
THURSDAY.
AVIATION...FOR HARRY REID...FOR THE 06Z FORECAST PACKAGE
SOUTHWEST WINDS OF 10 KNOTS OR LESS ARE EXPECTED THROUGH THE
OVERNIGHT PERIOD. EXPECT GRADUALLY INCREASING CLOUD COVER THROUGH
THE NIGHT WITH BASES LOWERING TO LESS THAN 10KFT AGL BY MID-MORNING.
SHOWER CHANCES WILL DEVELOP AS EARLY AS 12Z, BUT WILL BECOME MORE
LIKELY AFTER 15Z, WITH THE POTENTIAL FOR LIGHT TO MODERATE RAIN FROM
15Z THROUGH 00Z. CIGS WILL GENERALLY REMAIN BETWEEN 7KFT AND 9KFT
AGL, BUT COULD DROP TO AROUND 5KFT AGL AT TIMES DURING THE
AFTERNOON, ALONG WITH A 10 PERCENT CHANCE OF VISIBILITY REDUCTIONS
TO LESS THAN 6SM. ISOLATED CONVECTION IS ALSO POSSIBLE, MAINLY AT
THE ONSET OF PRECIPITATION. SHOWERS WILL END SUNDAY EVENING, WITH
GRADUALLY IMPROVING CEILINGS OVERNIGHT INTO MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW 100F THROUGH AT LEAST TUESDAY.
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...FOR THE 06Z FORECAST PACKAGE...EXPECT GRADUALLY
INCREASING CLOUD COVER OVERNIGHT FROM SOUTHWEST TO NORTHEAST, WITH
CIGS FALLING TO 8KFT TO 12KFT BY MORNING FOR ALL THE TAF SITES
EXCEPT KBIH, WHERE SCT HIGH CLOUDS ARE EXPECTED. SHOWER CHANCES WILL
START TO INCREASE AFTER 12Z ACROSS THE WESTERN MOJAVE DESERT AND BY
15Z ACROSS SOUTHERN NEVADA. CIGS WILL GENERALLY REMAIN AROUND 10KFT
AGL, BUT MAY LOWER TO BETWEEN 4KFT AND 6KFT AGL WITH SOME HEAVIER
SHOWERS THROUGH THE DAY. THERE IS ALSO A 10% CHANCE OF VISIBILITY
REDUCTIONS TO LESS THAN 6SM. ISOLATED AREAS OF CONVECTION ARE ALSO
POSSIBLE, ESPECIALLY AT THE ONSET OF PRECIPITATION. THE
PRECIPITATION WILL END FROM SOUTHWEST TO NORTHEAST SUNDAY EVENING,
WITH GRADUALLY IMPROVING CEILINGS OVERNIGHT INTO MONDAY MORNING.
SPOTTER INFORMATION STATEMENT
SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER OR IMPACTS ACCORDING TO STANDARD OPERATING
PROCEDURES.
DISCUSSION...SOULAT
AVIATION...PLANZ
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